The studies are designed to inquire into the nature of patients bearing intact primary malignant melanomas in order to determine the following aspects of this disease: 1. Basic work-up of a primary lesion. 2. The exact parameters required for assigning patients to a high risk primary category within six weeks of primary surgery and the parameters required for assigning a patient to a low risk category. These studies include parameters of the primary lesions and a variety of epidemiologic data from the patients. 3. The study of primary malignant melanoma is attempting to delineate the precise developmental biology of a neoplastic system in man. 4. Attempting to study comparatively the immunologic status of patients in high and low risk categories using percentage of T cells forming rosette; determination of cell mediated cytotoxicity to two reference melanoma cell types, determination of host blastogenic response to melanoma antigens. 5. The comparative epidemiology of high and low risk patients with primary malignant melanoma, attempting to study families with more than one member with malignant melanoma and also very young individuals developing malignant melanoma. 6. Additional studies include: The investigation of developmental biology of volar-subungual malignant melanoma, mucus membrane melanomas and an attempt to quantitate and qualitate the host cellular response to primary malignant melanoma.